Activatable UCL/CT/MR-enhanced in vivo imaging-guided radiotherapy and photothermal therapy

Although sophisticated radiotherapy (RT) technology has been widely applied in clinical oncotherapy, unsatisfactory therapeutic effects due to hypoxic tumor microenvironments and complications are still prevalent. Herein, copper sulphide nanoparticles (CuS NPs) wrapped on the surface of upconversion nanoparticles (UCNPs) via manganese dioxide (MnO₂) coatings were synthesized for O₂ self-supplementing and enhanced combinational RT/photothermal therapy (PTT). In our design, the nanoplatforms can be rapidly enriched at tumor sites by the enhanced permeability and retention (EPR) effect and respond to the tumor microenvironment. The surface MnO₂ coatings can interact with over-expressed H₂O₂ in tumors and cause an abundant generation of oxygen for hypoxic improvement, leading to an enhanced RT. More importantly, by irradiation with near-infrared light, the scattered CuS NPs can convert light energy into heat to destroy tumor cells and reinforce the therapeutic effects of RT. Furthermore, these NPs also displayed excellent performances in upconversion fluorescence imaging (UCL), computerized tomographic (CT) scanning and magnetic resonance imaging (MRI), demonstrating a potential imaging-guided cancer therapy system.